The present invention relates to the technical field of a crusher for crushing a fibrous material and a fiber-containing material such as wheat bran, and the like, and more particularly, to a mechanical crusher capable of finely crushing a fibrous material and a fiber-containing material at a high efficiency.
Mechanical crushers such as the swirl type crusher disclosed in Japanese Examined Utility Model Publication JU. 57-040104 B, the turbo type crusher disclosed in Japanese Unexamined Patent Application Publication JP. 51-064661 A, and the like have been used as an apparatus for crushing a powder-like fiber-containing grain material such as wheat bran to fine powder.
Various types of food that contains fibers are produced and distributed as beauty foods and health foods. At that time, it is preferable that the particle size of fiber-containing fine powder is such that a maximum diameter is 100 xcexcm or less and an average diameter is 30 xcexcm or less in order that these foods taste silky.
Further, in fiber-like powder for industrial use, for example, carbon fiber and the like used in a fiber-reinforced composite material, a material having a shorter fiber length is desired to improve mechanical strength by uniformly blending the fiber-like powder with a binder.
In the conventional mechanical crushers as described above, however, the number of revolution of a rotor must be increased to obtain fiber-containing fine powder having the aforementioned particle size with the maximum diameter of 100 xcexcm or less and the average diameter of 30 xcexcm or less by crushing a fiber-containing material. Thus, various problems arise in an efficiency of energy, a life of the bearing of the rotor, occurrence of noise and vibration due to the rotation of the rotor at a high speed, and so on.
Moreover, since there is a limit in an increase of the number of revolution of the rotor, powder and/or grains obtained by crushing a fiber-containing material by the conventional mechanical crushers are often mixed with powder which is not crushed to a desired particle size.
Accordingly, to obtain fiber-containing fine powder having a desired particle size, it is necessary to execute a process for removing coarse grains the particle size of which exceeds the desired particle size by means of a classification device such as a sieve, an air classifier, and the like, from which a problem is arisen in that a production efficiency is bad.
Accordingly, an object of the present invention is to solve the problems of the conventional art and to provide a mechanical crusher for a fiber-containing material capable of effectively crushing a fiber-containing material used for food such as wheat bran and a fiber-like material for industrial use such as carbon fiber and the like to fine powder having a maximum diameter of 100 xcexcm or less and an average diameter of 30 xcexcm or less as a particle size.
To achieve the above object, the present invention provides a mechanical crusher comprising a rotating shaft, a rotor mounted about the rotating shaft and having at least one sub-rotor containing a plurality of blades, a liner having a plurality of grooves formed on an inner peripheral surface thereof and disposed externally of the rotor with a predetermined gap defined between the inner peripheral surface thereof and an outer peripheral surface of the rotor, and a drive unit for rotating the rotor and coupled to the rotating shaft, wherein each of the plurality of blades of the at least one sub-rotor incline in a direction where flow of a material to be crushed is forced back.
It is preferable that each of the plurality of blades inclines at an angle of 10xc2x0 to 45xc2x0 with respect to an axial direction of the rotating shaft.
It is also preferable that disc-shaped plate members each having a diameter smaller than an outermost diameter of the at least one sub-rotor are disposed so as to clamp the at least one sub-rotor in an axial direction of the rotating shaft.
It is another preferable that the rotor further comprises at least one sub-rotor having a plurality of blades which are rectangular blades provided in a radial direction of the rotor and in parallel to an axial direction of the rotating shaft.
It is further preferable that a pitch of the plurality of blades on the outer peripheral surface of the rotor in a rotational direction of the rotor ranges 8 mm to 40 mm.
It is still another preferable that a size of the plurality of blades in the rotational direction ranges 2 mm to 10 mm and a height of the plurality of blades in a radial direction of the rotor ranges half of the pitch of the plurality of blades to five times the pitch.
To achieve the above object, the present invention provides a mechanical crusher for a fibrous material comprising a rotating shaft, a rotor mounted about the rotating shaft and having at least one sub-rotor containing a plurality of blades, a liner having a plurality of grooves formed on an inner peripheral surface thereof and disposed externally of the rotor with a predetermined gap defined between the inner peripheral surface thereof and an outer peripheral surface of the rotor and a drive unit for rotating the rotor and coupled to the rotating shaft, wherein a pitch of the plurality of blades of at least one sub-rotor of the rotor on the outer peripheral surface of the rotor in a rotational direction of the rotor is set to 8 mm to 40 mm.
It is preferable that the rotor further comprises disc-shaped plate members each having a diameter smaller than an outermost diameter of the at least one sub-rotor and disposed so as to clamp the at least one sub-rotor in an axial direction of the rotating shaft.
It is another preferable that the plurality of blades are rectangular blades provided in a radial direction of the rotor and in parallel to an axial direction of the rotating shaft.
It is further preferable that a size of the plurality of blades in the rotational direction ranges 2 mm to 10 mm and a height of the plurality of blades in a radial direction of the rotor ranges half of the pitch of the plurality of blades to five times the pitch.